Kiera Cameron is one of three central characters and is the sole female protagonist. She is a member of the City Protective Services (CPS) in 2077. She is transported back in time during the first episode, A Stitch in Time while watching over the execution of the terrorist group Liber8.[3] She then fakes her way into the Vancouver Police Department by posing as a detective from Portland.[4]

Starting from the first episode of Season 2, she became a lone wolf of sorts after Alec is alienated from her by a message from his future self. Agent Gardiner sees her turning invisible. Later on she uses the invisibility of her suit to work outside of the restraints of the VPD.[5] During the season's fifth episode she suffers from a mental breakdown, activating a Psychologist programme within her suit.[5]

In the finale of the second season she is betrayed by Alec who uses the Time Travel Device himself and is then captured by the Freelancers and imprisoned with Liber8 and Jason.[6]

In the season 3 premiere she and Garza attempt to escape from the freelancers but Garza is shot dead.[7] Kiera is then dragged before the freelancer leader, Catherine who explains that Alec's time travel is undoing the timeline.[7] Kiera agrees to help the freelancers and travels through using a device that takes her to the new timeline. She successfully free Garza in this timeline and makes a treaty with Catherine and the other freelancers to allow her to stop Alec from changing the timeline more than he already has.[7]

Green Kiera from the timeline that Alec created by time travelling is shot dead by a man named Brad Tonkin who was working with Curtis Chen.[8] Brad Tonkin was hit by a truck shortly after the murder[8] and wakes up a few weeks later remembering only Kiera's name,[9] and she ends up taking him under her wing[9][10] and later steals an Alzheimer's drug which in 2077 would become the illegal street drug "Flash" in order to help him regain his memories.[10] She discovers his true identity after they are abducted by Liber8.[8]

Nichols and Barry have both confirmed that there will not be a romantic relationship between Carlos and Kiera.[2]

Initially the character of Kiera Cameron was written as a character called Kyle but was rewritten as Kiera by Simon Barry.[2] Barry would also add in or change bits of the script while on set or during the script read throughs in order to encompass and incorporate Nichols personality. [2] Nichols has also revealed that she was sent the script by a friend and after reading the first ten pages of the script decided that she must go for the part,[2] she also stated that she performs all the stunts that the production team allow her to.[2]

Vancouver Police Department (VPD) Detective Carlos Fonnegra, Kiera's partner with the present-day police; he learns the truth about her time-traveler status in the second season episode "Second Truths". Throughout the course of the second season, Fonnegra becomes disillusioned with the VPD's changing police procedures and is seen shaking hands with and joining Julian (Theseus) at the conclusion of the episode "Second Time" with colleague Betty Robertson.

Erik Knudsen as the young Alec Sadler. As a teenager, before he went on to found SadTech, Alec is reclusive and prefers to spend time in his computer lab; there, he is able to communicate with Kiera through her cybernetic implants, which he discovers to be based on his own inventions.

Stephen Lobo as Matthew Kellog, a former member of Liber8. Kellog deserts from the group in Season One and hopes to build a new and wealthy life for himself in the past using his knowledge of the future.

Roger Cross as Travis Verta, a member of Liber8 and super-soldier, Kagame's right-hand man and former lover of Sonya Valentine. Since Kagame's death, he has been opposed to Valentine, Kagame's designated successor, seeking more violent methods and recruiting criminals into his version of Liber8. Travis appeared to die after falling to his death in "Second Time".

Lexa Doig as Sonya Valentine, a member of Liber8 and former lover of Travis Verta who is designated Kagame's official successor as leader after his death, and now seeking to reform the world through ideas rather than violence, and recruiting middle and working class people into her version of Liber8.

Tony Amendola as Edouard Kagame, the leader and spokesman of Liber8; he sacrificed himself in the finale as part of a larger plan. (Regular Season 1, recurring afterward)

Omari Newton as Lucas Ingram, a member of Liber8 and former SadTech engineer who was forced to defect to Liber8's cause. He is not a soldier, but his technical skills remain crucial to his colleagues in Liber8. He sided with Sonya during the Liber8 civil war. His mental status is questionable in recent developments of the conflict, and has been committed to a psychiatric ward, although he later escaped.

Luvia Petersen as Jasmine Garza, a soldier and member of Liber8. Garza is physically strong, agile and lethal, but mentally damaged from corporate imprisonment. She sided with Travis during the Liber8 civil war, and claimed to become Travis's current lover. Garza also has a connection with elderly Alec: apparently she intended to serve as his "insurance policy" if his younger self seems to deviate from his plans, although as with everyone else, she doesn't know if the purpose is to change Alec's path or ensure it.

Jennifer Spence as Vancouver Police Department Detective Betty Robertson, a colleague of Det. Fonnegra, who generally handles the computer side of their cases; recent evidence has suggested that she has begun to sympathize with Liber8's motives to the point of providing them with information for which she is arrested and placed in ankle monitor surveillance when her connection to Liber8 is revealed. She is later killed by a mercenary working for Greypoint Security when she was close to discovering their illegal operations. (Regular Season 1–3)

Brian Markinson as Vancouver Police Department Inspector Jack Dillon, Carlos and Betty's superior officer; he respects Kiera's insights despite the mysteries of her past. The red tape and politics of police work, that sees him joining Piron board of directors, begins to set him down a dark path that alienates Carlos and Betty, and even surprises Kiera.

William B. Davis as the elderly Alec Sadler in 2077. In the future, Alec founded SadTech in the later twenty-first century. He has risen to head one of the largest and most powerful corporations in the world, as its owner and CEO, his influence and technology dominate the North American Union. He was also a founding father of the Global Corporate Congress, and is currently Chairman of Superior Council. Alec is responsible for the presence of both Kiera and Liber8 in 2012; in season 2 it is suggested that he regrets having founded the corporate future world, due to all that has been lost to create it, and has set a plan in motion, with Kiera at the center, to change it – or perhaps ensure it.

Richard Harmon as Julian Randol, Alec's step-brother in 2012. Later in his life, he will be known as Theseus, the founder of Liber8 and mentor to Edouard Kagame. He is hired by Alec in Revolutions per Minute to act as an advisor for public affairs.

Ian Tracey as Jason Sadler, an alleged former employee of the same prison where Liber8 escaped from, thrown back in time to 1992, rather than 2012. His sanity isn't quite intact from his prolonged time alone; he has hinted that he has learned that there are other time travelers, capable of going back and forth through time, that are present in their current era, known as "Freelancers", but considering his mental state this information is of questionable accuracy. In the third episode of the second season, "Second Thoughts", it is hinted that he is Marc Sadler. It is revealed in "Second Time" that he is Alec's son in 2077 instead and that he played a major role in sending Liber8 back in time. Starting in Revolutions per Minute he becomes a beta tester for Alec's "Halo" project but his mental health begins to dettorgate and in 3 Minutes to Midnight he is responsible for attacking a random jogger and later he tries to kill Julian because of what he knows he will become.

Magda Apanowicz as Emily/Maya Hartwell, Alec's girlfriend. It is revealed in the second season episode "Second Degree" that she is working for Escher. She was killed by the Freelancers in pursuit of the time travel device in "Second Last". In the episode "Second Time", it is revealed that Alec likely plans to stop her death when he says "I have to save her" before time traveling to one week prior. In the modified timeline first revealed in "Minute by Minute", she murdered Escher.

Terry Chen as Curtis Chen, a member of Liber8. He is killed by Kiera's handgun's safeguard system but is later revived by the freelancers. Once resurrected he became devoted to the Freelancer Cause. He did however kill Green Kiera in the episode Minute by Minute and was then imprisoned by the Freelancers in Waning Minute but later escapes in the same episode. in 3 Minutes to Midnight, it is revealed that he was not responsible for Green Kiera's death but was working alongside someone who was.

Mike Dopud as Stefan Jaworski, a member of Liber8. He was the first of the Liber8 members to die in 2012 during a confrontation with Kiera Cameron and her partner Carlos Fonnegra.

Hugh Dillon as Mr. Escher/Marc Sadler, ex-freelancer, CEO and chairman of Piron, Alec's father, and a shadowy figure with powerful connections, who appears to know something about Liber8 and Kiera's true origin. He has protected Kiera and seeks to form an alliance with her, however his true motives are as yet unclear. In "Second Time", he revealed himself to be Alec's father. In the modified timeline first revealed in "Minute by Minute", he is murdered by Emily.

Nicholas Lea as Canadian Security Intelligence Service (CSIS) Agent Gardiner. He believes that Kiera is feeding information to Liber8 due to her anomalous background, although Kiera and Carlos have mistakenly speculated that he may be the mole himself. Later he and Kiera find a middle road when she asks him to help investigate the Freelancers. Gardiner is killed by the Freelancers for his efforts.

John Reardon as Greg Cameron, Kiera's husband. He is a SadTech project leader, and Alec Sadler is his boss. He is primarily seen in Kiera's flashbacks to her life in 2077.

Sean Michael Kyer as Sam Cameron, Kiera's young son. Kiera's abrupt separation from him causing her a degree of psychological anxiety. He is primarily seen in Kiera's flashbacks to her life in 2077.

Tahmoh Penikett as Jim Martin, politician and Carlos's friend. He is secretly working with Liber8 in his quest to become Mayor of Vancouver. He commits suicide in "Minute Men".

Michael Rogers as Roland Randol, Alec Sadler's step-father in 2012. Like his son, he is firmly against corporate leadership, but does not advocate violence to achieve Liber8's goals. He is killed in a police raid, when a sniper mistakes him for a hostile and shoots him.

Caitlin Cromwell as Elena, Kiera's Protector partner in 2077. She is revealed to have traveled back in time to the year 1975. She and Kiera briefly reunited in 2012 only to see Elena die shortly after from old age.

Adrian Holmes as Warren, one of the freelancers. He was sent back in time along with Jason from 2077.

Ryan Robbins as John Doe / Brad Tonkin,[11][12] a time traveller from 2039 who comes back in time to stop the alteration of the timeline from Keira's. He kills the Kiera who didn't follow Alec back in time a week with the help of Chen, after which he is hit by a van and wakes up in the hospital only remembering Keira's name. He later remembers his past life thanks to an alzheimer's drug. He is later captured with Keria by Liber8 where he reveals the future that is created. This causes rifts between the four remaining members of the group.